Protecting a 1/4" air line under the cab

what is the airline for?

Is it possible to tap into a line somewhere else and come from a different direction?

 

I am going to go with "go to an auto-salvage yard and ask for asbestos looking sheathing that goes around some exhaust manifold" as well as re-route & stand-offs

 

If you insulate the line for the purpose of protecting it that may cause the line to hold heat and cause failure. You could fabricate a sheet metal heat shield and hose clamp it to the exhaust pipe at that point or you could use a stainless braided air compressor hose in that section above the pipe, it is made to take the heat or a hard line in that section would work too. Leaving the line unsheathed will aid in keeping it cool. The heat shield on the exhaust pipe would really help dissipate heat when truck is not moving.

 

You may have no trouble with it at all with a free flowing exhaust. It's the ones that are all choked down with allot of back pressure that build so much heat in the pipes then radiating it everywhere.

 

Bender is right on, in the old days we used DOT copper tubing for the air lines as well as wire brade hose. The trailer dealerships for the most part still stock the DOT copper line, and "no", you don't want to consider standard water line copper tubing, it is more brittle and has a thinner wall thickness, it will not stand the vibration. You will still be able to use the same DOT brass fittings with the copper tubing, just remove the shiny stainlees steel insert that goes up inside the nylon line to keep it from collapsing, it won't work with the copper, and the copper won't cpllapse as bad as the nylon, just take a pair of plyers and grasp the stainless insert, and it will com right out of the fitting. Just use the copper in the area near the exhaust line, use nylon everywhere else.

 

They make high temp split loom fwiw. Personally I would take some half inch airline split it down the length, and zip tie it in plac over the 1/4 in stuff. You could also do a heat shield preferably attached to the heat source with an air gap. Or wrap with turbo tape.

 

Aluminum foil.

If it's really important line I would use a tube over the exhaust.

 

You can get the spark plug heatsheilds at napa I use them anytime I work on a cummins ism egr motor for the water temp harness.just use the plastic split loom cover and run the line with all the factory lines and up with the airlines that go to the cab air ride of airlines directly under the cab